A horizontal bar 1.5 metres long and of small cross-section rotates about vertical axis through one end. It accelerates uniformly from 1200 r.p.m. to 1500 r.p.m. in an interval of 5 seconds. What is the normal component of the acceleration of the mid-point of the bar after 5 seconds after the acceleration begins ?

• A. 2.7 m/s2
• B. 3.7 m/s2
• C. 4.7 m/s2
• D. 5.7 m/s2